In the reading and presentation of changing numbers, such as in reading and presenting the weight of a container being loaded or unloaded, certain problems arise when microprocessor-based systems are utilized. For example, if the analog weight information is converted to binary boded decimal (BCD) digits, the BCD digits are typically read one at a time. However, the analog data such as the weight information may be constantly changing during normal operation, such as during loading or unloading of a container. Thus during a "read" cycle, the digits might change.
An illustration of this problem may be found in FIG. 1. FIG. 1 illustrates a system that is being read between time t.sub.0 to time t.sub.3. During times t.sub.0 and t.sub.1, the weight is 99 grams. Sometimes between t.sub.1 and t.sub.2, the weight has changed to 100 grams. Thus from time t.sub.2 to time t.sub.3, the weight is 100 grams.
The problem occurs because the multiplexed data is read one digit at a time. Thus at time t.sub.0, the unit digit 9 is read, at time t.sub.1, the 10's digit 9 is read, at time t.sub.2 the hundred digit 1 is read, and at time t.sub.3 the thousand digit 0 is read. This results in an apparent reading of 0199 which is inaccurate because the correct reading should be 99 at t.sub.0 to t.sub.1 and 100 at t.sub.2 to t.sub.3.
A possible solution to this problem is the addition of hardware the latch the data so that the t.sub.0 reading remains until the end of t.sub.3. However, the addition of such hardware or circuitry to provide the necessary latch is relatively expensive.
Therefore, it is an object of the present invention to provide a system for reading changing data accurately without requiring latching hardware.
Other objects and advantages of the present invention will become apparent as the description proceeds.